1. Field of the Invention
The present invention relates to sheet slitting and winding devices, and more particularly, to a machine for separating double thin sheet, for longitudinally slitting the sheets, and for winding the sheet strips in lateral abutment onto a winding shaft.
2. Description of the Prior Art
It has become common practice to produce thin aluminum sheet, and especially aluminum foil in the form of a double sheet which is then separated into two sheets and longitudinally slitted into parallel strips. Heretofore, the longitudinal slitting necessitated the use of closely spaced double knives between adjacent sheet strips, in order to cut from the sheet a narrow strip which would then be sucked off by a vacuum pickup to create a small gap between adjacent strip coils on the winding shaft.
Ideally, longitudinally slitted sheet strips should be wound onto the winding shaft without gaps, in order to eliminate the loss and potential operating problems resulting from the gap production. For this to be possible, it is necessary that the sheet strips have absolutely consistant edges and are guided with absolutely no possibility of lateral drift. Obviously, the lateral drift between adjacent sheet strips is a function of the distance which they travel between the slitting station and the winding point on the winding shaft.
It has also been found that the problem of lateral drift is accentuated in the case of sheets which have been separated from a double sheet. The distance between the slitting station and the winding point is largely determined by the particular winding geometry of the machine which, as the winding diameter increases progressively, may undergo substantial changes from the smallest coil diameter to the largest coil diameter.